Some Forest History
Two picturesque pine stumps stood for years in the edge of a grove near my cabin. They looked as old as the hills. Although they had wasted a little through weathering, they showed no sign of decay. Probably they were the ruins of yellow pine trees that before my day had perished in a forest fire. The heat of the fire that had caused their death had boiled the pores of these stumps full of pitch. They were thus preserved, and would endure a long, long time.
I often wondered how old they were. A chance to get this information came one morning when a number of old pines that grew around these stumps were blown over. Among those that went down were three large and ancient yellow pines and several smaller lodge-pole pines. These I dissected and studied, with the idea that their annual wood rings, together with the scars and embossments, might give information concerning the death of the old brown-gray stumps.
A WESTERN YELLOW PINE
Two of the yellow pines showed two hundred and fifty-six annual rings; the other showed two hundred and fifty-five. All carried fire scars, received in the year 1781. Apparently, then, the stumps had been dead and weathering since 1781. The annual rings in the overthrown lodge-poles showed that they started to grow in 1782. Lodge-pole pines commonly spring up immediately after a fire; these had apparently taken possession of the ground as soon as it was laid bare by the fire that had killed and partly consumed the two yellow pines and injured the three scarred ones. Since the lodge-poles were free from fire scars, since the yellow pine showed no scar after 1781, and since all these trees had stood close about the stumps, it was plain that the stumps were the remnants of trees that perished in a forest fire in 1781.
Later, a number of trees elsewhere in the grove were called upon to testify, and these told a story that agreed with that of the trees that had stood close to the stumps. These stumps are now the newel-posts in a rustic stairway.
Near my home on the slope of Long's Peak are the records of an extraordinary succession of forest fires. During the last two hundred and fifty years eight large fires and numerous small ones have occurred. Each left a black, fire-engraved date-mark. The dates of some of these fires are 1675, 1707, 1753, 1781, 1842, 1864, 1878, 1885, and 1900. Each fire burned over from a few hundred to a few thousand acres. In part, nature promptly reforested after each fire; consequently some of the later fires swept over areas that had been burned over by the earlier ones. Here and there a fire-scarred tree, escaping with its life, lived on to preserve in its rings the date of the conflagration. In one old pine I found seven widely separated scars that told of seven different fires. In addition to the records in isolated trees, there were records also in many injured trees in groves that had survived and in ragged forest-edges where forest fires had stopped. An excellent check on the evidence given by the annual rings of fire-scarred trees was found in the age of the new tree-growth that came up in the fire-swept territory in which, or on the borders of which, were the telltale fire-injured trees.